Dental casting machine



Jan. 29, 1929. v

I. E. BRENNER DENTAL CASTING MACHINE Filed larch 28, 1927 Z Sheets-Shut. 1

2 Sheets-Slant 2 Q o P [41,

-wrmmumnmmu I 1 1 .l'iled llarc h 2a, 1927 Patented J an. 29, 1929.

UNITED STATES PATENT OFFICE.

ISIDOR EDWABD BRENNER, OF CHICAGO, ILLINOIS.

DENTAL CASTING MACHINE.

Application filed March as, 1927. Serial No. 178,961.

This invention relates to a machine for making dental castings, and is concerned p r1- marily with a type of construction which utilizes serially inertia, gravity, and centrifugal forces in the casting operatlon. Other features of improvement as well form partof the present invention of which a suggestive embodiment is set forth in the accompanying drawing in the manner following:

Figure 1 is a side elevation of the machlne in its entirety, the parts being in the normal position of rest;

Fig. 2 is a top plan v1ew thereof;

Fig. 3 is a sectional detail taken on line 3-3 of Fig. 1

Fig. 4 is a detail in vertical section taken centrally through parts;

Fig. 5 is a sectional detail of one end'of the mould shaft together with the proximate mounting therefor; and a Fig. ,6 which a view generally simllar to Fig. 3 shows a different form of mould box supported in place.

The present machine may comprise a base A from which upstands a pair of vertical supports B in spaced relation to provide near their upper ends hearings in which is mountthe mould and associated ed a shaft 10. Adjacent one end of the shaft I0 is shown a nut 11 forming a stop against which is rested a pinion 12 having a sliding splined connection with the shaft. A coiled spring 13 serves normall to position the pinion against the stop w ere it is in meshing relation with a segmental rack 14 carried upon a frame 15 which is pivotally mounted at 16 to one of the vertical supports B. As

part of this frame I provide also a handle 17v for swinging the frame upon its pivot whereby to rotate the inion 12'and associated shaft on which it is mounted,

Extending transversely from the shaft, preferably in the middle region thereof, is a rod 20 whereon is slidingly carried a weight 21 having screw means 22 for'locking the same in a fixed position of longitudinal adjustment. If desired, a head 23 may be fixed to the extremity of the rod whereby to constitute astop for preventing separation of the weight from the rod. This weight is in counterbalancing relation to a crucible and associated mould carried upon a second rod 25 also extended transversely from the shaft nection with a base 27 of a crucible frame 28 having a removable front plate 29 which may be secured in place as by one or more screws 30. The crucible frame is of box-like structure with a rear wall 31 slanted backwardly at an angle of nearly 45. Within this frame is received a crucible 32 of clay or other suitable material so formed as to provide an overhanding hood below which is a pocket 33 having a rear wall 34 sloping gently in an upward direction. Along its rear wall the crucible is formed with a nipple which protrudes through an opening in the back wall 31 of disposed in right angular relation to each other and each provided with an outturned' flan e 36. Equidistantly from these rails and elow them is a threaded shaft 37 having one end journaled at the rear of the crucible base. The other shaft end is swivelly sup- 1 ported within a bearing 38 depending from the two rails adjacent" their outer ends. A

knurled wheel 39 carried at the extremity of means therefor.

I have mounted upon the shaft 37 and in screw-threaded relation therewith. a radially 'movable carriage which is adapted to travel back and forth in response to turning movements of the shaft. This carriage includes a body 40 surroundingthe shaft, a neck 41 which extends upwardly between the two rails 35, and a head portion 42 from which upstands a web 43 which supports a clamping plate 44 in transverse relation to the shaft 37. This plate is also in parallelism with the rear wall 31 of the crucible frame, and is adapted to be moved toward and from the same. The head portion 42 of the carriage is slidably seated upgn the two rails 35 so as to furnish proper support to the clamping plate. The mould wherein the casting is formed may conveniently be enclosed within a form box 45 which is open at opposite ends. This box may be square as suggested in Figs. 1, 2, and 3, or round, as shown in Fig. 6. In either case it is adapted to be centered between the two rails 35 in a osition to receive molten metal which flows 0m thecrucible. This box, together with the mould therein, is held tightly in fplace against the rear wall of the crucible rame by the clamping plate 44 which bears with a dethe shaft provides a convenient operating sired pressure thereupon in response to adjustment of the shaft 37, in the manner pre- 7 viously described.

' ble quickly gets under way, and in doing so,

In the operation of the present machine the parts stand initially about as shown in Fig. 1. After reducing metal in the crucible to a molten state, the handle 17 is manipulated to draw the rack bar 14 in the direction of the arrow shown in the drawing, with a consequent rotation of the pinion 12 in the direction of the arrow shown in Fig. 1. The first movement of the crucible is in a direct-ion both down and under the'shaft 10, the crucible occupying initially about a mid position in the lower right quadrant of a circle having this shaft for its center. With an appreciable pull on the handle 17 the crucitakes advantage of the inertia of the molten metal which tends at once to climb over the rear wall 34 of the crucible. As the shaft movements proceed, the'crucible is swung more and more into a down position where a gravity force becomes effective to carry the metal into the mould. Before the gravity force is spent, a centrifugal force is developed which ultimately'acts alone to hold the metal in place while changing from a liquid to a solid condition. After the crucible has again come to a position of rest, the pinion 12 may be pushed in against the tension of the spring 13 following which the rack frame 15 is restored to its initial position without requiring further turning of the shaft 10.

The principle of operation which characterizes the present machine depends in part upon the initial position of the crucible relative to the shaft on which it is carried, and in part upon the manner in which the mould is associated with the crucible from which the metal is poured. In the construction shown, the rack mechanism is pivoted directly below the shaft 10, but with a preponderance of its weight to one side thereof, the handle 17 being brought to a position of rest against the pinion 12. This determines the initial position of the parts in which the crucible lies both below the shaft and off to one side thereof. With commencement of shaft movement-the crucible is moved down and under-the shaft so as to be tilted with the result that the molten metal fiows'over the inclined rear wall into the mould. The mould, it should be noted, is faced directly against the rear wall of the crucible which, as previously suggested, should preferably be inclined at an angle of approximately 45. From this position only a slight movement is necessary in order that the mould may receive the metal. Also it is important to note that the actuating means for the shaft, viz, the rack mechanism, can impart a movement in one direction only on account of the position of the handle 17 which initially lies adjacent the pinion 12. Because of this relamoans tionship of these parts, the rack mechanism is movable in but one direction, with the consequence that the crucible is rotated in the intended direction so as to perform a casting operation as herein described.

I cla m 1. In a dental castln machine the combination of a horizontal shaft, a pinion slidably holding the same normally in meshing rela-- tion with the rack mechanism, and a mould having a radial connection with the shaft and adapted to be moved through a circular path with rotation thereof, substantially as described.

2. In a dental casting machine, the combination of a rack mechanism, a pinion in mesh with the rack, a shaft whereon the pinion is mounted, means for shifting of the rack and pinion relatively in an axial direction whereby to disengage the one from the other, spring means tending normally to resist said shift, and a mould having a radial connection with the shaft adapted to be rotated thereby in response to actuation of the rack mechanism, substantially as described.

3. In a dental casting machine, the com bination of a rotatable shaft having a'radial' 4:. In a dental casting machine, the combination with a rotatable shaft of a counterbalanced frame having a radial connection therewith and adapted to be revolved thereby, a crucible removably carried within said frame and having a gently inclined rear wall which terminates in an'opening, a mould indepen lent of the crucible and disposed adjacent thereto, adjustable means. for holding the mould against the crucible with a variable pressure, and means for imparting a one-way rotation to the shaft whereby to tilt the crucible initially in a downward direction, to start a gravity flow of metal therefrom into the mould and in continuing such rotation at speeds sufficient to develop a centrifugal force which assists the metal flow into every part of the mould, the said means serving to position the crucible below the shaft and to one side thereof, substantially as described.

5. In a dental casting machine, the combination with a rotatable shaft of a crucible connected radially to the shaft, a mould positioned adjacent the crucible and inclined at an angle of approximately 45, 21 wall of the crucible adjacent the mould hazing gently inclined to facilitate movementef molten metal from the crucible into the mould when the crucible is first tilted, means connected with the shaft adapted to preserve the crucible normally in a down position to one side of the'shaft, the said means being adapted also to impart to the shaft a one-way rotation such that initial movement produces a down motion and tilt of the crucible to induce a gravity flow of metal into the mould and thereafter a centrifugal force which assists the metal fiow into every part of the mould, substantially as described.

6. Ina dental casting machine, the combination with a horizontal shaft, of means extended radially therefrom in \two directions. a weight adjustably mounted on one of said radial means, a crucible fixedly mounted on the other of said radial means, a mould adjacent the crucible and to one side and below the same, means associated with the mould for holding the same tightly against thecrucible, the crucible occupying a normal position of rest below and to one side of the shaft, andone wall of the crucible adjacent the mould bein gently inclined in an upward direction W iereby to permit flow of molten metal therefrom into the mould when the crucible is first tilted, and means for imparting to the shaft, a one-way rotation to tilt the crucible initially ina downward direction and thereafter continuing such rotation to develop a centrifugal force which assists the metal flow into every part of the mold, sub-' stantially as described.

7. A dental casting machine in which is combined a crucible and associated 'mould adapted to rot-ate about a horizontal axis, means whereby the crucible and mould assume an initial position below said axis and to one side thereof, the mould in such position having its open face disposed at an angle of about 45 to receive a gravity flow of metal from the crucible promptly upon movement of the latter beneath said axis of rotation, and means for imparting a oneway rotation to the crucible in a direction which proceeds at first downwardly and continuing such rotation at sufficient speeds to develop the centrifugal force which causes the metal to flow from the crucible and'into every part of the mould, substantially as described. r

8. A dental casting machine in which is combined a crucible and associated mould mounted to rotate about a horizontal axis,

therefrom when the crucibleis first tilted in response to a movement thereof beneath said axis of rotation, and means for imparting to the crucible and mould a one-wayrotation which causes the same to move downwardly at the start and on continued rotation assists the metal flow in every part of the mould by centrifugal force, substantially as described.

9. A dental casting machine in which is combined a crucible and associated mould mounted to rotate about a horizontal axis from an initial position in which the crucible is below and to one side of said axis, and means whereby to rotate the crucible in a single direction which swings the crucible initially down and under the said axis, the mould being faced radially toward the crucible whose outer wall is gently inclined to release a flow of metal into the mould in response to a force of inertia developed with first movement of'the crucible which is supplemented by a centrifugal force of increasing power as the rotation continues, substantially as described.

10. A dental casting machine in which is combined acrucible and associated mould mounted to rotate" about .a horizontal axis from an initial position in which the crucible is beloW and to one side of said axis, means whereby to rotate the crucible in a single direction which swings the crucible initially down and under the said axis, the mould being faced radially toward the crucible whose outerwall is gently inclined'to release a flow of metal into the mould in response to a force of inertia developed with first movement of the crucible which is supplemented by a centrifugal force of increasing power as the rotation continues, and a hood associated with the crucible affording protection against escape of metal therefrom, substantially as described.

11. In a dental casting machine, the combination with a rotatable shaft of a counterbalanced frame having a radial connection therewith and adapted to be revolved thereby, a crucible removably carried within said frame and having a gently ,inclined rear wall which terminates in an opening, a mould, adjust-able means for holding the mould closely adjacent the crucible, and

means for imparting a one-way rotation to the shaftwhereby to move the crucible initially downward causing the floor of the crucible to be moved away from the molten' metal and, by. virtue of the inertia of the molten metal, reduce the frictional resistance between the metal and the crucible, substantially as described.

12. In a dental casting machine, the combination with a rotatable shaft of a counterbalanced frame having. a radial connection therewith and adapted to be revolved there;

by, a crucible removably carried within said frame and having a gently inclined rear wall \vhlch terminates in an opening, a mould, ad-

justable means for holding the mould closely.

adjacent the crucible, and means for impart- 5 ing a one-Way rotation to the shaft whereby to rotate the crucible initially downward and, by virtue of the inertia and the gravity moans movement of the molten metal, bring the opening of the crucible under the downward moving met-a1 causing a gravity flow of metal 10 therefrom into the mould, substantially as described.

ll. EDWARD BRENNER. 

